The present invention relates to a leakage detector for endoscopes, and more particularly, to a leakage detector for endoscopes of the perfect watertight type.
For reasons of sanitation, endoscopes are always washed and sterilized after use. Considering the convenience of washing and the like, there are provided endoscopes which have an entirely watertight structure including operating devices thereof so that it is possible easily to wash and sterilize the whole body by immersing it in a washing liquid and an antiseptic solution. However, when there are defects in the watertight structure of operating devices or pinholes and cracks in a sheath of the endoscope's flexible tube washing liquid can leak into the inside of the endoscope. This is highly undesirable since corrosion is caused inside of the endoscope and the washing liquid may leak into the bundle of optical fibers in the endoscope, resulting in hindrance to transmission of light. In addition, it is possible that patients will be harmed if washing liquid which is leaked into the inside of the endoscope leaks out of the endoscope while in use. To prevent these problems, Japanese Published Unexamined Utility Model Application No. Sho 53-114891 discloses a method wherein the internal pressure of the endoscope is raised above the external pressure outside the endoscope by providing an opening for applying compressed air into the endoscope. As a result, the leakage of a liquid into the endoscope when immersed in a washing liquid is prevented. According to this method, it is advantageously possible to easily find out a location where air comes out in the form of bubbles from pinholes, if any.
However, it is necessary to properly choose a value of pressure to be used when compressed air is applied, otherwise there would be a likelihood that the endoscope itself may be damaged by the pressure. If the pressure is controlled using a pump, the apparatus becomes disadvantageously complex.
In addition, it is extremely inconvenient that in order to apply compressed air into the endoscope a pump for exclusive use is always provided by the endoscope.